1. Technical Field
The present invention relates to an intake air quantity control device for an internal combustion engine, and particularly relates to an intake air quantity control device including a rotational angle detector for detecting a rotational angle of a throttle valve.
2. Background Art
In conventional intake air quantity control devices that include a rotational angle detector for detecting a rotational angle of a throttle valve, there is a known intake air quantity control device in which a flat portion is provided at an end portion of a throttle shaft, and a supporting hole is provided at a rotor that is rotatably supported in a throttle body, and a rotational angle of the throttle shaft is detected by fitting the flat portion and the supporting hole with each other (for example, refer to Patent Document 1).
In the rotational angle detector, the flat portion at the end portion of the throttle shaft is arranged in parallel with an intake air passage of the throttle body in a state where the throttle valve is totally closed, whereby a deviation arising at a fitting portion is suppressed at a minimum value.
Moreover, in conventional intake air quantity control devices that include a rotational angle detector and control an aperture ratio of a throttle valve by a motor, there is a known intake air quantity control device in which a rotational angle detector and a cover for installing a drive unit are integrated (for example, refer to Patent Document 2).